1. Field of the Invention
The present invention relates to a method for the directional attachment of a scale element, such as a scale or a scale support or a scale guide device of a position measuring system to an installation face of a first body. The present invention further relates to a device for executing the method.
2. Discussion of Related Art
Such scales can be attached to machine tools or coordinate-measuring machines. The machines have at least two elements, which can be moved with respect to each other. The scale is affixed on one of the two elements and is then used, together with a scanning head located at the other of the two elements, for measuring the relative movement of the two elements.
Often, very long scales are needed for such position measurements at machine tools or coordinate-measuring machines. The scales must be fastened, aligned parallel with the measuring direction, wherein the measuring direction is predetermined by the guide devices of the machine tool or measuring machine.
Various steps have already been proposed for the attachment of scales.
In accordance with EP 0 388 453 B1, a self-adhesive tape scale is glued on by an adjustment device and is aligned in the direction of the guide sequence of a carriage of a machine tool or measuring machine. This type of fastening offers a good allocation of the tape scale to the scanning head, but can only be employed for highly elastic scales in tape form. The adjustment device is always attached to the carriage in place of the scanning head, so that the scanning head must be removed for aligning the tape scale, the adjustment device must be attached, then removed again after alignment, and the scanning head must be attached again. As a whole, this is very cumbersome.
It is alternatively possible, such as described in DE 197 00 367 A1, to provide lateral contact elements for aligning a scale, against which the measuring tape is placed.
An also widely used fastening method for thin scales consists in introducing the scale into a groove of a scale support. This is described on pages 58 and 59 of the company publication “NC Längenmeβsysteme” [NC Linear Measuring Systems] of the firm Dr. Johannes Heidenhain GmbH of September 1998. In this case, scale supports made of extruded aluminum are affixed to a fastening surface with an adhesive tape with glue on both sides, and thereafter a scale is pushed into the receiving groove of the profile. Here, too, the problem of aligning the scale support exactly parallel with the measuring direction also exists.
Alternatively there is the option of initially attaching a scale guide device aligned with the installation face, on which it is then possible in turn to align the scale itself.
Adjusting devices are always provided in connection with the attachment methods for scales, scale guide devices and scale supports so far known, which ate attached for this purpose to the machine tool or coordinate-measuring machine, and then must be removed again from the machine after the scale or the scale support have been attached.